1. Field
The present application discloses a self magnetizing motor and a compressor having the same.
2. Background
In general, a motor is a device for converting electrical energy into kinetic energy. Motors may be divided in direct current (DC) motors and alternating current (AC) motors according to a power source to be used. AC motors include induction motors, synchronous motors and commutator motors. The induction motors may be classified into a single-phase induction motor and a three-phase induction motor.
The single-phase induction motor has a relatively simple structure. Also, it is relatively easy to obtain a single-phase power source for such a motor. As a result, single phase induction motors are widely used in all sorts of electrical devices and appliances for domestic, office, industry and architecture. The single-phase induction motor cannot start rotating using just its main coil. For this reason, in addition to the main coil, these motors include a sub coil which receives current having a phase which is approximately 90 degrees out of phase with the current supplied to the main coil. The current applied to the sub-coil generates a starting torque. The main and sub coils are wound on a stator using a predetermined winding method.
In the related art single-phase induction motor, when an AC power source is supplied to the main coil and the sub coil during the initial starting procedure, a rotating magnetic field is generated. Once the rotor begins to rotate, the current supplied to the sub coil is stopped by a current cut-off device. Current is then only supplied to the main coil. Also, as the rotor rotates, an induction current is generated in conductive bars of the rotor.
The AC current applied to the main coil generates a rotating magnetic field which rotates at a predetermined speed which depends on the physical configuration of the motor. However, in related art motors, the rotor will rotate at less than the speed of the rotating magnetic field. The difference between the rotational speed of the rotating magnetic field and the rotating speed of the rotor is typically called “slip.”